Year	Percent
1970	87.26287
1971	87.59894
1972	88.17481
1973	88.7218
1974	89.48655
1975	89.7619
1976	90.48724
1977	90.74492
1978	91.40969
1979	91.84549
1980	92.25941
1981	92.66802
1982	93.05556
1983	93.61702
1984	94.15094
1985	94.48529
1986	94.80287
1987	95.27972
1988	95.5707
1989	96.00666
1990	96.42857
1991	96.67722
1992	97.06337
1993	97.28507
1994	97.78761
1995	97.98271
1996	98.16384
1997	98.33795
1998	98.77551
1999	98.93191
2000	99.21363
2001	99.48454
2002	99.74684
2003	100
2004	100.2445
2005	100.60168
2006	100.8284
2007	101.04773
2008	101.37457
2009	101.57835
2010	101.88889
2011	102.18818
2012	102.37069
2013	102.65393
2014	102.82427
2015	103.09278